This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Nilsson, T Articles by Isberg, A Search for Related Content PubMed PubMed Citation Articles by Nilsson, T Articles by Isberg, A

Virtual reality for simulation of radiographic projections: validation of projection geometry

¹ Oral and Maxillofacial Radiology, Department of Odontology, Ume University, Ume, Sweden; ² VRlab, Ume University, Ume, Sweden

*Correspondence to: Tore Nilsson, Oral and Maxillofacial Radiology, Department of Odontology, Ume University, SE-901 87 Ume, Sweden; Email: tore.nilsson{at}odont.umu.se

Received 31 August 2002; accepted 10 February 2003

Objective: To develop a software for virtual reality (VR) simulation of X-ray images based on perspective projections through a patient model derived from data from a CT examination and to evaluate the accuracy in the projection geometry obtained by the software.

Methods: A VR software was developed on a personal computer, with models of a patient, an X-ray machine and a detector. The model of the patient was derived from data from a CT examination of a dry skull. Simulated radiographic images of the patient model could be rendered as perspective projections based on the relative positions between the models. The projection geometry of the software was validated by developing an artificial CT data set containing high attenuation points as objects to be imaged. The accuracy in projection geometry was evaluated in a systematic way. The distances between two dots, representing the projected test points in the simulated radiographic images, were measured. They were compared with theoretical calculations of the corresponding distances using traditional mathematical tools.

Results: The difference between the simulated and calculated projected distances never exceeded 0.5 mm. The error in simulated projected distances was in most cases within 1%. No systematic errors were revealed.

Conclusion: The software, developed for personal computers, can produce simulated X-ray images with high geometric accuracy based on perspective projections through a CT data set. The software can be used for simulation of radiographic examinations.

Keywords: virtual systems; radiography; computer simulation; software validation